Comparison of zooxanthellae densities from upside-down jellyfish, Cassiopea xamachana, across coastal habitats of The Bahamas

Abstract

Abstract.-Anthropogenic disturbances may drive jellyfish blooms, and previous studies have suggested this is the case for upsidedown jellyfish (Cassiopea xamachana). Cassiopea were found to have higher mean zooxanthellae densities in human-impacted areas on Abaco Island, The Bahamas, suggesting that nutrient loading in impacted sites may be one factor driving zooxanthellate jellyfish blooms. Gut contents from Cassiopea medusae were positively correlated to zooxanthellae densities, indicating that heterotrophically-derived nutrition may be an important factor in facilitating increased zooxanthellae population densities. Understanding the mechanisms driving jellyfish blooms is crucial for developing effective management strategies in impacted coastal ecosystems.

Are Zooxanthellae Really Sensitive? Response of Zooxanthellae Size Exposed to Several Pollutants

“…These pollutants affect either directly or indirectly to a variety of organisms, both individually, population or community (Gray, 1992;Edinger et al, 1998;Meyer-Reil and Köster, 2000), The impact is highly dependent on the sensitivity of the organism to pollutants (Ambariyanto and Hoegh-Guldberg, 1996;Borja et al, 2000). Several scientists have reported changes in zooxanthellae which include decreasing the cell density, chlorophyll, mitotic index, and cell damage (Mercier et al, 1997;Ferrier-Pages et al, 2001;Owen et al, 2002;Cervino et al, 2003;Ambariyanto, 2011;Stoner et al, 2016).…”

Blue appendages and temperature acclimation increase survival during acute heat stress in the upside-down jellyfish,Cassiopea xamachana

“…In fact, Cassiopea sp. thrive in human disturbed environments (Stoner et al, 2011(Stoner et al, , 2016 and are expanding their habitat range. Our results may therefore reflect the underlying thermal tolerance of Cassiopea rather than environmental conditions of specific collection sites.…”

Experimental effects of multiple thermal stress events on chlorophyll-a content and size of <i>Cassiopea andromeda</i> and the role of heterotrophic feeding and <i>Symbiodinium</i> concentration

“…The association Symbiodinium-Cassiopea andromeda studied here presents biological responses to thermal stress that are also observed in hermatypic corals and other organisms used as models for climate change effects (Robison and Warner, 2006;Suggett et al, 2008;Jiang et al, 2017). The effects of temperature, Symbiodinium concentration, feeding and multiple stresses on the photosymbiotic holobiont have already been observed in reef corals.…”